Re: Basic xenstore questions (building a watchdog)

[Charles Duffy <cduffy@spamcop.net>]

Mark Williamson wrote:
>> I'm looking at building a xenstore-based watchdog, as described at
>> http://lists.xensource.com/archives/html/xen-users/2005-07/msg00597.html
>>     
>
> Sounds cool!
>
> I knocked up a little prototype of one some time last year.  The Xend code was 
> surprisingly tricky (couldn't get rebooting the domain to behave right, 
> although I didn't try very hard).  You'd be welcome to the kernel code if you 
> want to take a look, although it's very simple - the hacks required to the 
> softdog device in Linux were minimal.
>   
I would be very much interested in looking at what you've got so far, as 
an example if not a base.
> I'd suggest as an alternative to using the store, you might like to think 
> about adding watchdog functionality to Xen itself...  The advantage here is 
> that it also allows you to watchdog dom0, without requiring watchdog 
> hardware.  Timing out dom0 would reboot the system, a domU would just result 
> in its destruction (and the tools recreating it).
>   
It's a thought, yes -- but I'm already outside the realm of 
stuff-I-know, and I'd like to get at least *something* in working 
condition before I stray much further. Also, I'm under the impression 
that running softdog in dom0 with nowayout set should provide similar 
functionality -- perhaps I saw someone mentioning on the ML that they 
were doing just that?